This section provides background information related to the present disclosure which is not necessarily prior art.
A slug is a heavy projectile, usually made of lead or a lead alloy to provide rifle-like performance for a shotgun. There are several different types of slugs including Brenneke slugs, which are solid projectiles with fins formed on the exterior to reduce contact with the barrel of the gun and thereby, reducing friction and increase velocity. Another type of slug is a Foster slug, which has a deep hollow in the rear end of the slug. The forward end of a Foster slug is usually dome-shaped, while the rearward end is usually cylindrical. The cylindrical section usually has fins separated by the channels to minimize the friction on both the barrel and projectile and allow the slug to safely be swaged down when fired through a choke.
Conventional slugs provide a large, single projectile which can be very disruptive of the target in the localized area around the slug. However, conventional Foster slugs have a tendency to over-penetrate when fired at reduced velocities (1400 fps or less). Pre-slitted slugs, such as the slug disclosed in U.S. Pat. No. 3,138,102 (incorporated in its entirety herein by reference) have been developed. However, in order to prevent the slitted slug from prematurely segmenting, slitted slugs have generally been constructed, such that they only segment at relatively high velocities